Introduction
The domestic cat, Felis catus , is a very popular domestic animal
and is currently one of the most common carnivores in the world (O’Brien
et al., 2007). Unlike most domesticated animals, cats’ behavior has only
been slightly modified by domestication, as they generally retain the
ability to survive even in the absence of human support (Crowley et al.,
2020a). As a result, cats have widely varying degrees of dependence on
humans depending not only on the local ecological and cultural context
but also on whether they have an owner and the level of control
exercised by that owner. Crowley et al. (2019) distinguish a spectrum of
cats ranging from feral cats that are neither dependent on nor
controlled by humans to indoor cats that are fully confined with their
food, reproduction, and movements being closely controlled by humans.
Many developed countries have very large pet cat populations. In France,
for example, the pet cat population reached 15.1 million in 2020 (up
from 10.7 million in 2008) (FACCO/KANTAR-TNS survey 2020), with
potentially significant consequences on their wild animal prey.
Cats are generalist predators introduced by humans globally, and their
potential impact on wildlife is the subject of growing international
interest and concern (Loss et al., 2017; Crowley et al., 2020a). They
hunt many types of prey, including invertebrates and vertebrates, mainly
mammals, birds, and reptiles (e.g., Barratt, 1997; Castaneda et al.,
2019, 2020). The ecological impacts of cats have been shown to be
particularly severe on island ecosystems, where island vertebrates have
never coexisted with such introduced mammalian carnivores, and cats are
a major driver of extinctions of insular endemic birds, mammals, and
reptiles (Medina et al., 2011; Bonnaud et al., 2012; Doherty et al.,
2016; Palmas et al., 2017). On continents, cats have been shown to be
responsible for high vertebrate mortality (e.g., Blancher, 2013; Loss et
al. 2013), although the extent to which their predation represents a
form of compensatory or additive mortality is currently under debate
(Loss et al., 2017), as they consume the most abundant prey and rarely
the most vulnerable or declining species. For example, cats are probably
the single greatest source of anthropogenic mortality for birds and
mammals in the United States (Loss et al., 2013), although prey
population dynamics are rarely considered simultaneously with cat
predation pressure. In Australia, cats were shown to cause higher mammal
mortality than another threatening process, namely land clearing (Murphy
et al., 2020).
The majority of research to date has focused on the behavior and impacts
of feral cats (see the recent review of Loss et al. 2022), which are
dependent on the abundance and availability of natural prey species.
However, most pet cats that are fed by their owners retain some tendency
to hunt, and as they can reach very high population densities in areas
where humans are also numerous (Baker et al., 2005; Sims et al., 2008),
their overall impact can be severe. Several studies have shown that pet
cats have highly variable predation rates. For example, Baker et al.
(2008) and Thomas et al. (2012) respectively showed in the cities of
Bristol and Reading, UK, that approximately 60% of pet cats did not
return prey home in the study period. Loyd et al. (2013) observed a very
similar proportion (56%) in a suburban area of southeastern USA.
Similarly, Tschanz et al. (2011) observed that pet cats in a rural Swiss
village considerably varied in their hunting activity, with 16% of cats
accounting for 75% of the recorded prey, thus highlighting the
importance of identifying the factors that determine the predation rates
of individual cats. Cechetti et al. (2021a) recently reviewed the
drivers of hunting behavior in domestic cats. For the authors, whereas
general cat hunting is mainly driven by evolutionary constraints and the
associated physiological and nutritional requirements, the causes of
variation in hunting behaviors among pet cats mainly relate to prey
availability in the environment and the owners’ practices. These
practices include the level of outdoor access given to their cats, the
amount and quality of the food provided, and the amount of time spent
playing with the cat (Cechetti et al., 2021b).
Variations in hunting activity have also been linked to the individual
characteristics of cats such as their sex, age, and body size (Kays et
al., 2004; Moseby et al., 2015), although a number of studies have
failed to find an association with these factors (Woods et al., 2003;
Tschantz et al., 2011; Loyd et al., 2013; Cordonnier et al., 2022).
Recently, Cecchetti et al. (2021a) hypothesized that personality could
be a significant factor contributing to variations in hunting activity
between cats. Over the past few decades, it has been recognized that in
numerous animal taxa ranging from invertebrates to vertebrates,
individuals show different behavioral tendencies that are consistent
over time and across ecological contexts, a phenomenon commonly known as
animal personalities (Réale et al., 2007, 2010; Wolf et al., 2012). For
example, boldness, aggressiveness, or sociability are commonly studied
animal personality traits (Réale et al., 2007). Personality traits are
frequently correlated: for example, animals that are bolder in risky
situations also have a tendency to be more aggressive toward
conspecifics, resulting in what is known as “behavioral syndromes”
(Sih et al., 2004). Animal personalities have substantial consequences
for numerous ecological processes (Wolf et al., 2012; Spiegel et al.,
2017; Brehm et al., 2019). Regarding predator-prey interactions, several
studies have shown that individual differences in predator behavior can
influence hunting (Pettorelli et al., 2011). For example, in several
predator fish species, bolder individuals have a markedly higher
predation rate compared with shyer ones (Ioannou et al., 2008; Rhoades
et al., 2019). In their review of the drivers of hunting behavior in
domestic cats, Cecchetti et al. (2021a) speculated that cats with
certain personality traits, particularly those with high levels of
boldness and extraversion, could potentially be more motivated to hunt
wild prey. To our knowledge, this hypothesis has never been
investigated. It is therefore the main objective of our study to examine
this potential link between personality and predation in domestic cats.
Presently, in behavioral ecology studies, personality traits are usually
estimated with the following approaches (Freeman et al., 2011):
behavioral coding in which behavioral observation data are collected by
researchers in either natural (i) or experimental settings (ii), and
trait assessments (iii) in which the people who know the animal complete
a survey describing the degree to which it shows particular personality
traits. In domestic cats, although the first studies tended to use
behavioral coding (Gartner et al., 2013), personality trait assessments
based on a survey of the people familiar with the animals, usually their
owners, are now more common (Wedl et al., 2011; Bradshaw et al., 2016),
as they are both a reliable and time-efficient method (Bennett et al.,
2017). These studies (reviewed in Gartner et al., 2013; Vitale Shreve et
al., 2015; Mikkola et al., 2021) usually produced between one and seven
personality factors, with the three most common factors being the
personality traits of sociable, dominant, and curious, albeit with
varying names. In this study, we used the Feline Five personality model
of Litchfield et al. (2017), which consists of five personality
dimensions in domestic cats: neuroticism, extraversion, dominance,
impulsiveness, and agreeableness (see further details in the Methods
section).
In this study, our primary
objective is to determine whether the personality traits of pet cats are
related to their hunting activity. To this end, we surveyed a large
sample of cat owners living in France and estimated the personality
traits of their cats using the Feline Five personality model of
Litchfield et al. (2017) as well as the frequency of birds and mammals
returned home by the cats as reported by their owners. Following
Cecchetti et al. (2021a), we expected that cats with “low neuroticism
(boldness, leading to travelling, exploring) or high extraversion
(curiosity, leading to boredom), would potentially be more interested in
hunting wild prey.” To control for potential confounding factors, we
also included questions about variables previously shown to influence
pet cat predation: type of environment around the home, time spent
outdoors, individual characteristics, and breed (Robertson, 1998;
Lepczyk et al., 2004; Kauhala et al., 2015; Salonen et al., 2019;
Castañeda et al., 2019, 2020; Cordonnier et al., 2022).